Patient baseline characteristics
| The Netherlands | UK | Italy | Germany | Spain | |
| Treated/not treated n | Not treated 59 | Not treated 187 | Treated 3 | Treated 116 | Treated 9 |
| Male sex, n (%) | 33 (55.9) | 119 (63.6) | 1 (33.3) | 76 (65.5) | 6 (66.7) |
| Age at baseline years | 46.7±7.6 | 52.3±8.7 | 61.0±6.0 | 53.4±9.7 | 53.0±4.8 |
| Smoking status | |||||
| Never, n (%) | 4 (6.8) | 28 (15.0) | 1 (33.3) | 26 (22.4) | 0 (0) |
| Former, n (%) | 55 (93.2) | 159 (85.0) | 2 (66.7) | 90 (77.6) | 9(100) |
| Pack-years | 17.2±10.1 | 20.7±21.3 | 15±15 | 15.4±12.5 | 17.3±5.3 |
| Baseline FEV1 % pred | 47.3±9.1 | 46.4±9.6 | 37.3±4.9 | 46.2±10.1 | 47.2±7.7 |
Data expressed as mean±sd unless otherwise indicated. FEV1: forced expiratory volume in 1 s.